If you didn't know better, you might conclude from my writings that
I detest CFL bulbs. I really don't. In fact, I rather like them for
most applications. My house is full of them.
What I detest is
a world of bureaucrats that have determined that Edison's paradigm-changing
incandescent light bulb is such an evil device that they have conspired
to ban it off the face of the Earth. Based largely on fallacious, contrived
"scientific" data about anthropogenic (human-caused) global warming,
the wizards of smart declared that the incandescent bulb is singularly
responsible for hurricanes, species migration and extinction, disease,
and crop failure. It simply must go.
All praise be to the United
Nations heads of state and to lawmakers on Capitol Hill for caring so
much about little 'ol us. Can I have an "amen!"
Ever eager to
please, but certainly in nowise complicit, industry chieftains have
fallen in line and produced that which will appease our self-appointed
Earth Sentinels: the compact fluorescent light bulb. All hail. Ave CFL;
we have been instructed and admonished to adore you, for you are Earth's
Not so fast.
on the left, incandescent on the right. (note the background
Let us honestly and practically compare the incandescent bulb to the
CFL from a design, manufacturing, and lifecycle perspective - as we
have practiced in the "real world" throughout our careers as engineers
From a business perspective in a free market,
manufacturing any product requires an ability to sell it at a profit
to customers who decide on their own to buy your widget rather than
someone else's widget, or to buy no widget at all. The simpler the product
is to design, manufacture, distribute, sell, and dispose of, the more
attractive it is to the vast majority of consumers. From an environmental
impact perspective, fewer and less toxic materials, simpler manufacturing
machines and less manual labor, low bulk and light weight packaging,
and long lifetime expectations equate to a greener endeavor. Making
household light bulbs is not rocket science - at least it didn't used
The utter complexity of an incandescent bulb is mind-boggling.
Shown to the left is the innards of a standard 60 W incandescent light
bulb. Mind-boggling, isn't it? There must be more than 9 components
- and that is not counting the glass bulb! Here is a list of the components
that I see after removing the external glass for inspection.
• 1, Stamped metal screw base / electrical contact • 1, Metal disk
electrical contact at base • 1, Blown glass base/insulator •
2 metal electrodes • 3 metal filament supports • 1, Filament
(tungsten) • 1, Blown glass filament support structure • 1,
Glass electrode separator • 1, Blown glass outer bulb • Solder
to external electrode connections • Trace of zirconium getter (remember
as in tubes?) to eliminate oxygen • No hazardous / toxic materials,
except a smidge of solder (Pb-free?)
Total parts count - about
12 (not inc'l solder and getter).
Manufacturing is likely fully
automated from beginning to end, with no human intervention other than
loading raw materials and performing some level of inspection at the
end. A couple old movies are available on the Internet showing light
bulb factories back in the early to mid 1900s where women assemble the
bulbs by hand at a work station and then the glass forming and fusing
is done by machine, with other workers moving the bulbs from place to
Now let's take a look at the wonder device that has rocked
The entrails of a CFL bulb - so elegantly simple!
PCB top side (left) and bottom side (right)
For the sake of this article and to keep from having to use somebody
else's copyrighted photographs, I willingly sacrificed a perfectly good
26 W (100 W equivalent) compact fluorescent bulb by cutting open the
plastic base with a hacksaw. Goggles and gloves were worn during the
disassembly because I would hate to spend my final days as a blind man
or suffering from being poisoned by toxic ingredients getting into my
blood stream through a cut. Fortunately, vast experience combined with
luck resulted in no need to dispatch a HazMat team to the Blattenberger
Being the clever guy that I am, I managed to open
the base in a way that allowed the bulb to still operate.
of my motivation for doing the disembowelment was reading comments on
a website where someone claimed that the new CFL designs used all surface
mount components. I did not want to risk doing a report based on bad
information. As it turns out, this newly purchased CFL is made up of
nearly all leaded components. There are a couple SM resistors on the
back side of the printed circuit board, though.
As done for the
incandescent light bulb, here is a parts list for the CFL.
1, Stamped metal screw base / electrical contact • 1, Metal disk
electrical contact at base • 1, Molded plastic base • 1, Molded
plastic top • 1, Twisted glass tube assembly • 1, Phosphor coating,
mercury (vapor) • 1, Printed circuit board (2-sided) • 6, SM
resistors (1206) • 1, Transformer • 2, Wire-wound inductor
• 2, Transistors (TO-247) • 4, Film capacitors • 1, Tantalum
capacitor • 1, Fuse • 6, Diodes • 2, Hookup wire (3", 22AWG)
• 4, Wire-wrap posts • 4, Wire to bulb electrodes • 2, Glass
electrode plugs • Phosphor • Mercury • Some hazardous /
toxic materials (Hg), and some solder (Pb-free?)
count - about 42 (not inc'l solder and glue).
It is highly doubtful
that assembly of this CFL bulb is fully automated. Since it was made
in China, most likely peasants getting paid a couple bowls of rice per
day sit at their work stations contemplating suicide while being forced
under threat of imprisonment to meet a quota that would satisfy expectations
of the benevolent beings who have mandated that the world produce no
more of Edison's atrocities by the year 2012. But don't let that bother
you. Otherwise, those CFLs would cost you many times more than the $3
to $6 a piece you are now paying if they were made here. Americans don't
need no stinking jobs. Be happy. Be green.
labor, the manufacturing process for CFLs obviously requires much more
in the way of equipment. A glass blowing machine for a simple Edison
bulb does not need to be high precision or move in more than one axis.
A CFL tube needs a 3-D motion machine with complex software to drive
it. Both incandescents and CFLs require a furnace and/or flame to aid
glass forming and fusing. The CFL's PCB is likely hand-stuffed and soldered
by reflow, which requires a very hot, fuming molten bath of solder to
accommodate the high temperatures of Pb-free solders. Of course each
of the electronic components has its own environment-killing trail of
raw material mining and processing, manufacturing processing, packaging
and greenhouse gas producing transportation costs.
incandescent is a simple momentary contact, go-no-go procedure. Testing
a CFL requires a test station populated with equipment of greater complexity
since they must meet current waveform and EMI regulations. I did not
find any data on the scrap rate of CFLs versus Edison bulbs, but you
have to believe CFLs are more likely to be DOA or experience infant
mortality in the factory.
CFL voltage multiplier waveform - 56 kHz sine wave
While on the topic of EMI, when was the last time your incandescent
bulb interfered with anything due to electrical noise being generated
internally? On rare occasions I have literally heard the filament of
an incandescent bulb make an audible hum when being used with a rheostat
dimmer. I have never personally experienced any electrical interference
from a CFL, but I have had them scream like a banshee when used with
a dimmer (well, maybe not like a banshee, but loudly). However, since
inquiring minds want to know, I laid my oscilloscope probe next to the
traces for the transformer on the PCB to sniff out a signal. It measured
to be a 56 kHz sine wave (no attempt to measure voltage was made). What
operates at 56 kHz that might be affected? Nothing that I could find
in a Google search. It apparently is a common switching power supply
frequency. You might not want to use one in a light fixture near where
you are testing unshielded circuits, though, because there is absolutely
no shielding in the base of the bulb. If you see a blip on the spectrum
analyzer at around 56 kHz, turn off the lights to see if it goes away.
As for average lifetime of a compact fluorescent versus an incandescent
bulb, real-world numbers are typically vastly different than laboratory
numbers. Specsmanship driven by politics undoubtedly favored higher
numbers for the CFL bulb and lower numbers for the Edison bulb. I have
had incandescents last many years, and have had at least three CFLs
fail in the few years I have been using them extensively. One CFL failure
was due to a light fixture globe pressing against the gas tube and cracking
it at the base. CFLs often do not fit handily into older light fixtures.
Maybe newer fixtures are designed to allow more space for bulbs, especially
in the z-axis. The Internet is full of accounts of people who are sorely
disappointed in the premature failure rate of CFLs, particularly in
ceiling lights in hot environments where the electronics overheat.
The procedure for safe disposal of a CFL is about as ridiculous
as the recommended safety steps for responding to a car accident involving
an electric vehicle with a battery breach. Area evacuation, safety gloves
and goggles, inhalator, masking tape, and a vacuum are needed to properly
rescue the world from a CFL compromise incident. I'm not sure if mercury
exposure level tags are required for emergency responders. If an incandescent
bulb breaks, you sweep or vacuum up the glass and get on with life.
Not to fret if you break a CFL, though, because the caring folks at
the EPA have prepared this handy
PDF document instructing how to survive CFL breakage. It is best
to read it now and be prepared for the inevitable. Does your government
love you or what?
I recently wrote a
Cool Product topic on a combination CFL/halogen bulb being produced
by GE that solves the undesirable feature of CFLs where they emit a
lower level light when first being turned on. GE engineers imbedded
a halogen bulb within the curly-Q tube to provide extra light when first
turned on, then switch it off after a predetermined time to save energy.
Maybe some day I will get hold of one of those bulbs and do a parts
count on it. They are expected to cost $6-$10 each.
So, do you
really believe that the CFLs are the planet saver that they are claimed
to be? I am not convinced at all. I use them in ceiling lights where
the bulb sockets are rated for 60 W (most are if you look) because I
can use the 26 W, 100 W equivalents and end up with much more light
after they warm up. I also use them in my gooseneck type workbench light
since it ends up in my face sometimes while building a model airplane
or repairing a watch band. Other than that, it really does not matter
to me which bulb I use. If I had to use exclusively either incandescents
or CFLs, Edison's miracle would win hands down.
"The mechanized production of Duro-Test light bulbs is filmed
as a dance to the tune of the Brandenburg, as choreographed filaments,
glass, and metal combine in a dynamic finale." (thanks to Hugh for this link)
the pic to watch the Centennial Bulb cam in action. The Centennial
Bulb, the longest burning light bulb in history, is now now in its 110th
year of illumination (as of 2011). Will there be Centennial CFL?